This invention relates to methods and apparatus for use in a multimedia system. More particularly, the invention relates to editing, transferring, storing and playing back a multimedia composition so that multiple multimedia compositions are able to share the same multimedia data.
Efficiently editing, playing back and broadcasting multimedia data is a priority in the news industry. Multimedia data includes audio and video data collected from various sources such as video cameras, satellite, video and audio tape, compact disc, etc. An editor typically creates a news clip from multimedia data source material and the edited news clip is physically transferred to a playback device for broadcast.
Networking advances have automated the process of transferring of the edited news clip to the playback device. In such systems, a news clip is created from source material and edited at one of a plurality of editing workstations connected to a network. The edited clip is given an identifier (ID) and electronically transferred from the workstation to a playback device which can store the clip for later play to air. The playback device then plays the news story to air when the producer queues the ID of the clip.
The foregoing network, however, may waste bandwidth and memory by re-sending and restoring the same multimedia data used in different edited clips. For example, an editor sends a finished news clip to a playback device and wants to make minor changes. The editor may wish to delete five seconds of a thirty second news clip which was previously sent to the playback device. In such a case, the editor edits the clip at the workstation and resends the entire clip minus the five seconds which were deleted. Thus, the playback device stores two clips, both of which contain the same portion of multimedia data.
Another example of wasted bandwidth is the common occurrence in news journalism wherein a promotional clip is used in conjunction with a story. In such a case, a short clip of a larger news clip would be created for use as a promotional clip. The clip consisting only of the promotional clip would need to be sent, and the larger clip that contains the promotional clip that is used when the news story airs would be separately sent and stored in the playback device. Thus, in both examples cited above the identical multimedia data is transferred to, and stored within, two locations within the playback device.
A method and system is provided to avoid the duplicate storage and transfer of multimedia data in a playback device, thereby increasing system bandwidth and available playback memory. A multimedia composition which represents a compilation of edited source material is created and transferred to the playback device. The composition is examined to determine whether the multimedia data referred to in the composition is already stored in the playback device. If the data is stored in the playback device, or in transit to the playback device, it is not transferred to the playback device.
In one aspect of the invention, a method is provided for sharing data that includes the steps of creating a multimedia composition which references data, transferring the multimedia composition to a first location, determining whether the data referenced by the multimedia composition is contained in a storage area associated with the first location, and transferring the data referenced by the multimedia composition to the storage area only when the data is not already in the storage area.
In another embodiment, a multimedia system is provided that includes at least one workstation to create a multimedia composition which references data, a playback device coupled to the workstation to store and play multimedia compositions created by the workstation, and a transfer tool. The transfer tool transfers the multimedia composition and the data referenced by the multimedia composition from the workstation to the playback device. The transfer tool is adapted to only transfer data referenced by the multimedia composition that is not stored in the playback device.
In another embodiment, a method of deleting multimedia data in a device containing multimedia compositions and data referenced by the multimedia compositions is provided. The method includes determining how many compositions refer to particular portions of multimedia data, determining which portions of multimedia data no compositions refer to, and deleting the multimedia data that no multimedia compositions refer to.